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The Pain and Peril of Bonking in Cycling: How to Avoid the Unbearable Ride

When it comes to endurance events, the word “bonk” is often associated with “hitting the wall.” 

Riders experience this feeling when they run out of energy suddenly and unexpectedly. The legs of their body turned to cement suddenly while a person still moves at a manageable speed. A tired body, dead legs, and dizziness force you to stop.

One of the first references to the athletic term “bonk” was found in a film produced in the mid-1950s. This film showed that cyclists would bonk if they did not take a break or eat. 

Bonking in Cycling

In short, they would reach a limit dictated by their bodies and uncontrolled by their minds. Several people have reported that the feeling is similar to being hit on the head.

Hopefully, now you understand how important it is to understand bonking. Therefore, we have created this article where you’ll get to know everything about bonking in cycling. 

From causes and symptoms to how to deal with and prevent them from happening in the first place. We have discussed it all. So, keep reading to familiarise yourself with this term and to avoid it from happening to you.

What is Bonked Cycling

Biologically, bonking occurs when your body’s energy stores run low after a high-intensity workout. This means that your body and mind have run out of glycogen for your muscles and glucose for your bloodstream.

When you exercise at a low or moderate intensity with a heart rate of around 120 beats per minute. Then your body burns fat for a more extended period of time.

However, workouts at high intensities, such as exercise that maintains a heart rate closer to 160, cause your muscles to burn glycogen very rapidly.

A lack of these stores is like running out of gas since they burn much faster than fat. 

Athletes who often work out for more than 90 minutes at a time, such as distance cyclists, should be concerned about this issue. Because this is the point when your body uses up the glycogen it has stored from your earlier diet.

Warning Signs: Recognizing the Symptoms of Cycling Bonk

  1. Nausea
  2. Dizziness
  3. Feel Anxious
  4. More Hunger
  5. Shaking Hands
  6. Physically Weak
  7. Heart Palpitations
  8. Poor Coordination
  9. Cognitive Impairment

Cycling Bonk Causes — Understanding “Hitting the Wall”

In short, bonking is when your blood sugar drops too low (hypoglycemia), and you run out of fuel. 

The long answer is a bit complex. Your muscles are kept contracted by adequate and continuous supplies of glucose as fuel for long-distance exercise. There are several sources of glucose:

  • Bloodstream: Quickly depleted by high-level exercise.
  • Muscle Cells: Normally, most people can complete a 90-minute workout without fatigue.
  • Liver: Deliver enough glucose into the bloodstream to meet the body’s demands.

You can run all your body functions properly for hours on end with this amount of glucose at rest. 

But when you exercise hard, your stored glucose can quickly be depleted. This can be seen in endurance events like a five-hour bike race and an Ironman triathlon. It can be disastrous for your mind and body if you don’t continually add more fuel.

Remember, muscles aren’t the only body parts that require glucose. The brain requires glucose as well. This means your brain may also experience cognitive symptoms if your glucose level is exhausted and you hit the wall.

The dramatic impact of Bonking Cycling on your Health & Well-Being

Several significant problems can arise if the body goes into bonk mode. Let’s take a closer look at each of them one by one.

1. Heavy Muscle Loss

Fueling your body properly is essential when you’re participating in a lengthy training session. To accomplish this, it is crucial to consume plenty of sports drinks, carbohydrates, and other glucose resources before, after, and during the training session. 

If you don’t consume enough carbohydrates, your body will begin to rely on burning fat and proteins as energy sources. This ultimately will result in muscle damage. So, avoid creating such situations for your body.

2. Hit Immune System Hard

Physical exercise can strengthen the immune system and help the body adapt while training. Overtraining and bonking can, however, have a detrimental impact on your immune system. 

Riding at a high pace for prolonged periods of time or in intensity may suppress your body’s natural anti-inflammatory response.

In other words, if you overtrain, you increase your chances of getting sick or infected.

3. Affect Endurance Athletes Training

Bonking in cycling leads to lots of losses for professional cyclists in terms of training. Particularly since bonking directly affects our brain and physical health. Now let’s understand it better.

Brain Bonks

A brain’s energy comes from glycogen stores. You may temporarily lose focus, motivation, and ability to make decisions if you hit the point of bonking, where your body’s glycogen deposits have got completely empty. 

In spite of the fact that these effects are short intervals only. But they can be extremely dangerous when they occur in certain situations.

Physical Breakdown

You can become fatigued and stressed when your body reaches its exhaustion point. Exercise that causes long bouts of intense physical activity triggers cortisol production. A stressful environment can worsen existing health issues and cause physical pain.

4. Glycogen Stores Depletion 

Moderate-intensity rides burn between 600 and 800 calories an hour. Each individual’s figure will vary depending on the time, intensity, and weight of that person. 

Remember, as intensity increases. Your body burns glucose more quickly than fat.  And your chances of bonking increase if you do not consume carbohydrates during high-intensity rides lasting more than 2 hours.

The body metabolizes approximately 50% glucose and 50% fat when you ride at a low to moderate intensity (50 to 60% FTP). As a result, you can ride for longer periods of time (2 to 2.5 hours) before having to replenish your glycogen stores.

5. Dehydration

Cyclists may become severely dehydrated when unable to drink adequate water during training. Bonking, fatigue, and cramping can result from dehydration. In addition to being dangerous, chronic dehydration can also slow cognitive ability.

Learn how to overcome Bonking and maximize your Cycling Performance

When we talk about bonking in cycling, there are a lot of things we should take into consideration. We have shared some of the most influential and practical tips in this section. For the best results, consider them.

1. Maintain Blood Glucose Levels 

The ideal amount of carbohydrates per hour is 60-90 grams. It is possible to absorb energy even more quickly when you consume foods that contain fructose (the sugar from fruit) along with glucose, such as dried fruit and natural energy bars. 

However, overeating can lead to gastric distress, such as cramps, bloating, and slow digestion, so keep an eye on your portion sizes. You can avoid the bonk by eating little and often to maintain your blood sugar levels.

Start eating after 20 minutes of your ride and do so every 20-30 minutes. Keep bite-size snacks in your back pocket to keep your glycogen stores topped up, even if the going gets tough.

Tips to delay Glycogen Depletion

It is generally believed that the average human body can store 600 grams of glycogen. There is a wide variety of factors that influence this, such as fitness level, size, eating habits, and any recent exercise one has done. 

A healthy liver has about 100g of glycogen, while the rest can be found in muscles, which is logical since it’s those muscles that use glycogen for power. 

Bob Murray, a renowned expert on carbohydrate fuelling, estimates that a trained cyclist stores up to 50% more glycogen in the muscle parts than a sedentary person. Moreover, a ‘super compensated’ rider can store even another 50%. 

Are you interested in knowing how? Then consider incorporating the below-mentioned points in your diet.

2. Consume Carbohydrate-Rich Drinks 

Cycling performance is adversely affected by dehydration. The level of hydration in your body has a significant impact on blood plasma volume. A decrease in plasma volume and an increase in body temperature occur as you become dehydrated. 

Do you know what this means when you ride? It basically makes it impossible to exert the same amount of power throughout an endurance event, and these effects become more apparent when the event goes way longer.

Adding more water to your cycling regimen will help prevent dehydration. Despite this, the problem is a bit more complex. Sweating not only causes us to lose water but also sodium. 

Losing fluids can result in hyponatremia if only water is used to replace them. It is a condition in which blood sodium levels are diluted, and it can be deadly. Drinking too much water and losing a lot of sodium leads to this problem. 

Fortunately, you can always ensure that you have drunk enough water during your ride by utilizing the right hydration strategy. 

When it comes to filling your bottles, there are a lot of options available. 

You can drink water or a sports mix, depending on your hydration and sports nutrition needs. Choosing the right hydration drink for cycling is really a matter of taste, weather conditions, and intensity levels. Here are some options. You can choose one that fits your needs.

a. Cycling Electrolyte Powders & Drinks

The main focus of these drinks and powders is to provide potassium, sodium, and other electrolytes along with a limited amount of carbohydrates. You can drink electrolyte drinks as long as you consume enough calories amount from other sources such as chews, gels, and bars. 

b. Hydration Tabs & Mix

The next option is to use hydration tablets. In these mixes, carbohydrates and electrolytes are usually present. Approximately 3-4% of these drinks contain carbs, which support the movement of water and sodium through the small intestines.

c. Carb Drink Mix

A carb-dense drink mix is another way to hydrate while cycling. There are usually more carbs in these drinks than in hydration mixes, but the sodium content is almost similar.

Drink according to your body’s needs when cycling. To reach your goals, you should learn your needs and take the weather and intensity factors into account.

3. Fuel Up with Natural Energy Bars

Energy bars and whole-natural foods are great for providing your body with easy-to-digest fuel. The importance of good-tasting and smelling food cannot be overstated, as they make you look forward to those bite-sized energy intake moments. 

You won’t be motivated to fuel yourself if you don’t like the taste, and you will find it more challenging to force yourself to eat.

Remember, your digestion begins with your eyes and nose. Saliva breaks down food into energy when your mouth waters. As soon as the glucose hits your mouth, your body releases more glucose into your bloodstream. Therefore, taste really matters a lot.

The best energy bars are made with wholesome ingredients that taste delicious and trigger all your digestive systems to send energy directly to your muscles.

4. Take the right amount of Protein

Inactive people need less protein than endurance professionals. This is due to the stress endurance training places on muscles and tendons. Hence, obtaining enough dietary proteins is essential for maintaining and repairing protein structures.

When the body is under stress, its own protein is used to some extent as an energy source and needs to be changed with dietary proteins, especially amino acids that the body cannot make. These factors can all contribute to endurance athletes’ increased protein requirements.

According to leading scientists, adults who train between 1 and 3 hours per day should consume about 1.6 to 1.8 grams of protein per kg of body weight. 

All cyclists who consume the required energy will easily digest this amount through their diet to meet their training and performance needs.

For road cyclists who train very hard and/or follow an energy-reduced diet, 2.4 grams of protein per kilogram of body weight per day may be beneficial for optimum body composition.

5. Eat Wisely

It’s essential to eat various healthy foods in the months and weeks before you go on a long-distance bike ride to boost your performance and provide energy. Maintaining a well-balanced diet for the long term is essential if you wish to become the best cyclist possible.

When training for endurance cycling, you should consume the following foods:

  • Meatballs and spaghetti
  • Bowl of chicken, rice, and vegetables
  • Veggies and hummus on grilled chicken sandwiches
  • Bowl of rice, salmon, and vegetables with smoked salmon
  • An avocado or hummus-topped wrap with chicken and vegetables
  • Sweet potatoes and vegetables grilled with a turkey burger on the grill

Here are some suggestions for what to eat just before a long ride:

  • Protein shakes
  • Toast and eggs with whole grain
  • Yummy spinach, fruit, and yogurt smoothie
  • Banana slices and peanut butter on a toasted bagel with a cup of juice
  • An oatmeal bowl topped with mineral and vitamin-rich fruits and a cup of juice

6. Develop a proper strategy before the ride

Most cyclists make the mistake of assuming they don’t need to replenish glycogen until they’re well into a ride. Researchers from Maastricht University tested this theory by observing ten male participants for three hours. 

In the experiment, athletes were observed to consume sports drinks throughout the activity, not just at the end when a bonk threatened to hinder their performance. This significantly improved their average cycling speed. And also diminished their chances of getting bonked.

It’s, therefore, crucial to start sipping soon after you start riding so that your glycogen levels remain high. Don’t wait until the deed is almost complete before taking action.

Before your ride, you should make a strategic plan. Decide what you will eat and drink before heading out for a ride. To ease this process, you must determine how long your energy supply will last. Determine the water, energy bars, and sandwiches you need for a ride.

No matter what technique you use, make sure you plan prior. Otherwise, it will be too late once you’re on the bike to make good fueling decisions. As soon as you start bonking, eating can be challenging since you’ll be experiencing nausea. 

Taking little fluids with your food will give you the refreshing taste of carbs, and your brain will usually respond positively to it. The last tip is to know how much carbohydrate you should eat during a ride if you want to avoid bonking.

Strategies to avoid Bonking in Cycling and maximize your performance

Glycogen is produced in the body by glucose, which is generated by carbohydrates – the body’s essential energy source. It takes time for this process to complete, so you should plan ahead. Because the moment you bonk, it’s too late.

The following are three basic rules for preventing bonking while cycling:

1. Pre-race carbohydrate consumption should be high

If you plan to ride for a long time and at high intensity, you will need plenty of fuel. Protein isn’t a good idea at this time. Take advantage of your body’s stores by eating rice, bread, potatoes, or pasta.

2. Carry energy drinks for long rides

It is recommended that you bring energy drinks rather than water if you intend longer rides like more than 90 minutes. 

Whenever you are riding a long distance, drink your energy drinks early on to give your body time to digest them. 

The carbohydrate stores in your body are burned down by enough food you ate 90 minutes ago. To prevent bonking on the trail or road, eat and drink carbs throughout your ride.

3. Slow down in case you feel something wrong

As you increase your intensity level, your body burns fatter than glycogen. It is recommended that you ride slower if you don’t have an energy drink.

You have to realize that there is no quick fix if you bonk on a ride. You can help your body recover by eating or drinking a lot of simple sugar, but it needs time to do so. Do not ignore it and seek medical attention if it occurs. 

Prevention, however, is the best course of action. Giving your body the fuel it needs well in advance will make it easier to tackle those extreme rides with a clear head and strong legs.

4. Training Program to Beat Cycling Bonking

Before going for a long ride where bonking chances are really high. Try training yourself to handle that situation well. To avoid getting bonked in the first place, follow these two tips for yourself.

Cardiovascular Exercises

The most common way to perform bonk training is to exercise on an empty stomach first thing in the morning, when glycogen stores are low, consume coffee or caffeine equivalent to two or three cups of coffee, and run or cycle for 20 to 90 minutes at a casual pace (60 percent of maximum heart rate). 

To sustain your exercise efforts above 70% of MHR (maximum heart rate), glucose is the only fuel that can supply and support your efforts. This is why when you bonk, your body instead dips into fat and protein stores. After training, please take a regular breakfast. 

Bonk training can also be done in another way. Experts recommend performing two workouts on the same day. The first one is in the morning, and the second one is in the afternoon. 

When you do a second workout within a few hours of the first, there is not enough time for your muscles to replenish their glycogen stores between workouts. Hence, this can be an effective strategy for you.

Pacing Skills

A good pace can prevent you from bonking. Consequently, if you set your target speed too fast, you run out of fuel quickly and will likely bonk due to burning carbohydrates faster than you expected. For your best performance in a ride, practicing your pace is crucial.

The process of improving your pacing capacity is not easy. It will require a lot of practice on your part. Keeping one’s pace when biking isn’t easy. It takes countless miles on the road and circuits around the track to acquire an intrinsic sense of pace. 

Here are a few tips you might find helpful:

a. Patience Is Key

The Roman Empire wasn’t built in a day. The same is true for your pacing skills, which require a lot of effort, time, and dedication. Pacing can be challenging to control, but it’s an essential skill for improving fitness and biking faster. A pivotal quality to achieving pacing is patience.

b. Invest in a bike computer

Bike computers, like Garmin or Wahoo, are excellent tools. By using these tools, cyclists can keep track of their speed and find ways to improve it. A bike computer can significantly improve your ability to maintain a consistent pace.

c. Pay attention to your breathing patterns

Be aware of your breathing patterns to be able to feel the speed. Once you’ve decided on a pace for your workout, pay attention to whether your breathing speed or rhythm changes to determine if you’re speeding up or slowing down accidentally. 

Tracking all your gradual improvements plays a vital role in preventing you from hitting a wall.

d. Stay hydrated and avoid running out of energy

You must stay hydrated and consume enough carbohydrates and proteins to avoid running out of energy and, ultimately, bonking. 

Do Male Cyclists have A higher risk of Bonking

According to trusted resources, Yes, males are at a high risk of bonking. And the reason for this is more muscle mass and strength they carry with them. 

When males ride longer, they can cover more distance and that too very rapidly. Because of this, they are capable of maintaining more. And unintentionally hits the bonking door. 

On the other hand, women have less strength and muscle mass compared to males. This makes them stop before bonking in cycling. 

Note: Women are also found hitting the wall. However, the number is relatively low when compared with men.

How can Anxiety lead to Cycling Bonk

Professional riders are always under pressure to give their best. This is where they encounter stress and anxiety before the competition.

And to excel, they cross their bodies’ physical limits. Which ultimately leads to bonking in cycling.

Professionals must be given proper anxiety training. Plus need to be wisely guided to keep complete confidence in their capabilities.

Because when riders lack these two essential skills. They don’t understand what’s right for them and unfortunately hit the bonk early.  

How much time is required to recover from Cycling Bonking

According to the literature, your body’s glycogen stores can be restored to optimal levels after 24 hours of aggressive carbohydrate replenishment. 

However, practical experience suggests that the time frame could extend up to 48 hours or even longer, depending on the severity of the case or the number of carbohydrates consumed.

The moment you hit a point in which you are seriously struggling, this is the time of the day when it is game-over for that particular day for you. There is no quick fix to this problem. 

Ensure to get enough rest and make a serious commitment to eating right. For a quicker and healthier recovery.

It’s better to avoid bonking too often in the first place because the recovery period can be quite long after a bonk. You lose 1-2 days of decent output each time you do this. And the overall effectiveness of your training regime can be significantly reduced by this. So, always say no to such situations.

What immediate actions to take when you Bonk

If you experience any warning signs from your body, especially if you have been cycling hard for a couple of hours, you should stop cycling and eat some simple carbs that can be absorbed quickly.

Drinks with sugar, such as Gatorade and Powerade, fruit juice, or an energy gel washed down with water are the best sources. There are also straight sugar options, such as gum drops, hard candies, and jelly beans. 

Solid foods and energy bars contain complex carbohydrates that can take longer to digest during a bonk. So, avoid them for the timing.

Depending on the severity of the bonk, you may still be able to continue riding (a bit slower) if you catch it early enough. If you’re really having trouble, you should stop, go eat and recover for a while before continuing.

Unraveling the Mysteries of Bonking, Fatigue, and Cramping: A Comprehensive Comparison

Fatigue: The sensation of tiredness and the associated decrease in muscular performance. You can generally think of it as a body’s safety mechanism.

Cramping: When cycling, leg cramps may occur due to fatigued muscles caused by repetitive use. In turn, this fatigue leads to a breakdown of our normally efficient neuromuscular pathways which are responsible for our muscle movement.

Bonking: A point where the body feels extremely weak, shakes, goes light-headed, burns glucose, gets nervous, emotional, confused, and even irritable. At the most extreme point, this can lead a person to a coma situation too.

Fatigue to Cramping to Bonking Stage

After a long ride, the first thing a rider feels is fatigue. Where he doesn’t want to continue riding but mentally motivates himself to continue. This slowly turns into a cramp. In this phase, your muscles start giving up and send continuous brain signals to stop. 

But at this stage, the rider somehow manages to keep going. Then he reaches the final stage, which is called bonking. 

Although riding in the very first stage, i.e., fatigue is not recommended. But somehow, still, cramps and fatigue can be recovered quickly. 

However, when a rider reaches the bonking stage he loses his thinking and reaches a blurred vision state. That’s not only hard to recover soon but also very severely impacts your body.

Cycling in Bonking — Final Thoughts

All cyclists experience bonking at some point, but it can be prevented with proper carbohydrate intake, energy bars, and adequate hydration. 

A cyclist’s pace will greatly improve if he or she loads the body with enough carbohydrates before an event. 

Also, keeping a good pace prevents cyclists from burning out. Be mindful of your pacing when training for a ride to avoid burning out. 

You can only achieve success with a great strategy, so eat well before your event, improve your pacing, and refuel while on your way to avoid “hitting the wall.”

Still, if you have any suggestions or doubts or something that I have missed, feel free to drop a comment below. I will be more than happy to assist you with your query. Please follow our Facebook Page for more guides like this.

Have fun riding…..

Frequently Asked Questions — Cycling in Bonking

What does bonking feel like?

A true bonk can be more than an unbalanced feeling or drowsiness. The numb sensations are accompanied by nausea, severe physical weakness, poor communication, and an awful feeling. Bonking is mainly caused by exercising, hypoglycemia, and low blood sugar.

Does bonking burn fat?

Bonks or bonking means a period where a glycogen storage unit is depleted. Cycling is called bonking, and runners are called hits. Body Training is a workout plan intended to aid in weight loss. While bonking only adversely affects your body. And nothing more than that. 

How do I stop bonking?

Eat carbs before racing. It’s good to have plenty of energy during an intensive biking session. You can even bring energy drinks during a ride. 

When you ride for a period of over 90min, always take a water bottle and an energy drink. In case the body is giving a not-well signal, then stop.

How do you recover from bonking on a bike?

The only possible solution would be to drink water to get fluid to your body but not the entire body unless you have avoided the consequences. 


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Hey Folks! I’m Jacob. I am a passionate, adventurous cyclist and my biking philosophy is to have fun, I felt the need to share my knowledge and learn more about bikes. I always ensure I adhere to all road rules. I hope that you will give biking a try. It’s a great way to get fit and have fun.

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